Stove-pipe seam lock



Reb. 1'9, v193,5. J. J. HoLuB sTovEPIPE SEIAM LOCK Filed Feb. 26, 1934 Patented Fein.y 19', 1935 UNITED STATES;

lrnualv,frv oFrlcs- 4 invention relates tepipes such asthesheetf metal. pipes whichy are usedin connectionwith stoves, furnaces, and the like. More specically my improvement isdirected to means, for p re` *5 venting the accidental opening ofthe seamor connection that is madelongitudinally of? a pipe` sectionfor joining the edges of, the metal blank. v It'has been the practice among;4 manufacturers of stove-pipes to Vprovide intercalated seamsfof edges offl the sheet-metal blank so when these edges are brought togethertoiorm the blankintd a tubular shape these ilaps will be caused 'tovinff terengage and thereby maintain the s hapeof the;

pipe. Heretoforeseveral methods-have Ybeen devised in attempts 4to-llockthe bent-packjlaps either together or to the adjacent wall of thejpipe, but such. attempts have been successful -only to V`a minor extent because of inherentdefects rin the structures.V f

I. h avedevised;` 'dependable and eiective meanswhereby the edges of the sheetmetal blank. may beY readily connected to form a tubular -pipeqand when connected by `such-r means the. structurel is -rmly lockedY so that the joint or seam may not b e released by alateral circumferential movement or by lateral dislodgment, I havebeen able tosuccessfully accomplish this result by providing 4 stops at or adjacent the sea-m-u that areengaged by portionsof. the opposite edges of.` the blank s o that" relative lateral movement is'prevented v The improvements which I have: devised arenovel and simplein` construction whichnneces-y" sarily provides afstructurethat is eajsyto manip u late as well as one which is economical to manufacture so that it does. not increasetheretailprice of the article. Furthermore, myimproved pipe is dependable when in use both before and afterf assembly with other sections ofrpipe. The-foref' going are. several of the objects which Vhave mind in devising my improvements, and further objects will 'be apparent to others skilled intli'e' art after my inventionfis understood-` Ii prefer topra'cticemy'inventiony and'to acA` complish; the numerous objects thereof; inA sub` stantia-lly the mannerj hereinafter fully described' arid:V asl more particularly pointed` outiin the claims. Reference-'is madeto the accompanying t drawing that forms a partv caf-this. specifcaton.

In the drawing:-

Figure 1 is a vertical side-1elevationy of1 arr-endportion-of a stove-pipe-made according tothe preferredY embodiment of myinventionf.

Figur-e2 isV a fragmentary: transverse" section' to a larger scale for clearness.

Figure A3 is ai fragmentary transverse section taken in the plane of line 3 3 of Figure 1 and thereof taken on line 2- 2 of Figure 1 and ldrawn `showing the manner of asof the Vpipe blankV prior to lock- 4 Figure 6is a view sembling the edges ng`-- m f 'Iliemdrawinglis tobe vunderstood asbeing more or` lessfschematic and vis, for the purpose'of dis- 15 closing typcalembodirnents of my invention, the proportionssbeing exaggeratedvin Figs. 2,7 3 and 5. In this-drawing, likereference characters are employed to designatelike parts Wherever they appear the different;views.

The structure disc1osedin 1igs. l, 2, 3-,and'6 will rst .be described. The pipe consists of anY initially hat rectangular sheet-metal blank ofu suitable gauge for the service required, and whichl Y is, preferably rolled during fabrication to incor- 25 porate therein the desired curvature for forming` nal edges of the blank providethe respectiveportions of the seamwhichmaintains the structurein its completed state. One portion o f thev 30- The other or cooperating edge portion of the: 40 blank has a longitudinalshoulder 14 that extends in the opposite direction to shoulder 10 vto pro' vide an outwardly disposed offset portionil and beyond'th'isshoulder 147 thefbl'ank' is given a reverselend` 16 to provide a free flap 1'7 thatprof 45 jects towards the shoulder 14; VWhen assembled, the edges of the blank are intertted with each other by insertingiiapl'l into the space or cha-'nnel'between the other ap 13 and theV adjacent oset portion 11. bendsE 1"2}and 16 at or adjacent" the respectiveshoulders14 and'V 10` substantially'.A in the manner illustrated in enlarged .detailin Figure 2;

When the structure is AVassembled as above de scribedthe engagementlot the flaps-1in. the .re-e 65 This will dispose the reverse 50.

spective channels prevent disassembly of the intercalated seam due to relative lateral or circumferential movement of the edges in the directions of the arrows (Fig. 2). In order to prevent accidental relative movement in the opposite directions I have provided stops 18 and 19respectively against each of which an opposite portion of the seam structure will abut. The stops are formed by deflection of the metal at or adjacent or within the seam. l v

In the structure shown in Figs. 1, 2, 3 and 6 the stops 18 and 19 consist of relatively short up-struck portions located approximately in the longitudinal planes of the respective shoulders 10 Y and 14 so that adjacent portions of the reverse bends 16 and 12 respectively abut the `respective stops in substantially the. manner disclosed in exaggerated detail in Fig. 3. It will be noted that the stops project in opposite directions from l the blanks; that is, the stop 18 projects outwardly from the pipe andthe stop 19 projects inwardly stops may be modified and changed without de-J' parting from the principles of my invention. Therefore, I have disclosed another aspect of my invention in Figs. 4 and 5k of the drawing. Referring particularly to the exaggerated view (Fig. 5), it will be seen the structure forming the seam is substantially the same as that which isrdisclosed in the preferred type.

The shoulders 10 and 14 provide the inwardly and outwardly disposed olf-setportions l1 and 15 and such off-set portions have reverse bends 12 and 16 to provide the intertting free flaps 13 and 1'?Y to form the intercalated seam. Anup-struck stop 20 is formed intermediate the longitudinal edges of flap 13 with its ridge disposed outwardly of said flap. The otherstop 2 1 is located intermediate the longitudinal edges'of theoil-set portion 15 between the shoulder 14 and `the reverse bend 16 with its ridge extending inwardly. When the parts of this seam are assembled the operative portions of the stops 20 and 21 are adapted to abut each other and'prevent relative lateral or circumferential movement of the stops past eachother. Y Y Y In order to interfit the respective sections of the seam when assembling lthe structure, the blank is held in cylindrical form and then warped slightly in either direction, as illustrated in Fig. 6, so that the corners of the blank are disposed the one above the other and with the lower corner below the lower end of the stop on the other edge portion of the blank. In this position the ilaps may be readily interengaged, after which the corners are moved towards each other. 'vThis permits the portion of one side of the seam which is to abut the stop on the other portion to be moved longitudinally until it has beenrpositioned alongside the stop or the stops have been disposed alongside each other. In such positions the accidental opening of the seam is prevented in an eiective manner. Y

WhatI claim isz.- Y

l. A stove-pipe comprising a cylindrical body made from a metal sheet the proximate edge 1 portions of the sheet provided with reverse bends that formturned-back marginal flaps extending in opposite directions circumferentially of the body and interlocked with each other, and shoulders formedin the sheet, portions of said shoulders being projected upon both sides of the, medial circumference of the stove-pipe and engaged with said reverse bends.

2. A stove-pipe comprising a cylindrical body made from a metal sheet the proximate edge portion of the sheet provided with reverse bends that form turned-back marginal flaps extending in opposite directions circumferentially of the body and interlocked with each other, and shoulders formed in the sheet, circumferentially alined portionsV of said shoulder'sjbeing projected` upon both sides of the 'medial circumference' of the stove-pipe and engaged with said reverse bends. 3. A stove-pipe comprising a cylindrical body made froma metal sheet, off -set marginal portions extending along the proximate edges of the sheet,

vv.bent-back flaps within said off-set marginal portions that are interlocked Witheach other, and

longitudinal shoulders connecting the off-set marginal portions and the body of the sheet, a. portion of each shoulderbeing extended upon the opposite side ofthe medial circumference or Vthe ing stop along al portion of the inwardy 'formed' shoulderY engaged by the reverse bend onV the other edge -of the sheet, and an inwardly projecting stop valong a portionv of the outwardly formed shoulder engaged by the reverse bend on the other edge of the sheet, whereby relative circumferential movement ofthe structure to disengage said flaps is prevented. Y

5. v-A-stove-pipe comprising a metal sheet, inwardly and outwardly formed shoulders "spaced from the respective longitudinal edgesY of the sheet providing off-set edge portions, reverse bends lindsaid off-set portionsproviding interengaged longitudinal flaps, the sheet adjacent the inwardly formed shoulder providedfwith'an outwardly 'projecting stop; and the sheet adjacent the outwardly formed shoulder provided with an inwardly projecting stop, each stop beingA engaged by the reverse bend on the other edge of the sheet. Y

from the respective longitudinal edges of the sheet providing off-set edge portions, reverse bends-in said off-set portions' providing interengaged longitudinal ilaps, theinwardly formed shoulder having a stop that Vprojects outwardly of lthe pipe, and the outwardly formed shoulder having a stop that projects inwardly of the pipe, whereby each stop is engagednby the reverse bend on the other edge of the sheet. Y y

'7. A stove-pipe comprising a single metal sheet one proximate edge portion having a reverse bend providing an 'outwardly disposed flap, and an outwardly projecting abutment adjacent' one end of the pipe and disposed in thebody Yof the sheet alongside'the free edge of said flap; the other proximate edge portion having a. reversel bend providing an inwardly disposed nap, and an inwardly projecting abutment opposite vtherst-named abutment and disposed .in the body of the sheet alongside the free edge of the secondnamed ap; said flaps intertted to provide a, seam whereby the bend at one edge of the sheet iS engaged with .the abutment 011 Vthe @heutige and vice versa to prevent relative circumferential movement of the assembled structure.

8. A stoVe-pipecomprising a single metal sheet the adjacent edges of which sheet'are yshouldered to provide respectively inwardly and outwardly extended marginal olf-set portions; a bent back flap on the inwardly extended off-set portion, and an outwardly projecting abutment adjacent the shoulder forming said inwardly extended off-set portionya bent back flap on the outwardly extended oif-set portion, and an inwardly projecting abutment adjacent the shoulder forming said outwardly extended off-set portion; said -aps being interengaged to provide an intercalated seam with the bent edge of one flap engaged with the abutment on the opposite marginal portion of the sheet and vice Versa.

' JOHN J. HOLUB. 

